FDTD-based simulation and optimization of open plan offices involving novel acoustic lattices and retroreflectors

It is estimated that open office space already accounts for about 70% of total office space and the proportion will continue to rise, based on an estimate of 36 minutes of ineffective working time per day due to acoustic disturbances. The international standard ISO 3382-3 even states that “the majority of open office spaces with poor acoustics that meet the design objectives are uncommon in reality”, which is a clear indication of the difficulty of solving the problem of sound interference in open office spaces.

This paper investigates the optimization of noise reduction strategies in open-plan offices, focusing on using the Finite-Difference Time-Domain (FDTD) method for simulating sound propagation and reflection. By leveraging novel Cube Corner Reflectors (CCRs) as retroreflector arrays, the study aims to address challenges related to speech privacy and noise distractions in shared office spaces.

The FDTD algorithm simulates acoustic fluctuation methods to model sound propagation and reflection, providing detailed insights into how sound behaves in different open-plan office configurations. Additionally, the study integrates signal processing techniques, including direct sound elimination and energy calculations, to accurately evaluate the effectiveness of the retroreflectors in various environments. The simulation leverages GPU acceleration and multithreading to enhance the computational efficiency of the FDTD method. Moreover, the results are reconstructed and processed using octave band filtering and energy calculations, this involves squaring the signal energies and applying weighted calculations to evaluate the energy distribution across different frequency bands.

The study confirms that combining CCRs with conventional acoustic treatments significantly improves the acoustic performance of open-plan offices. CCRs can improve the sound environment of an open plan office by maintaining high speech intelligibility near the speaker and providing voice support for his/her own speech, while at the same time lowering the STI at a distance to minimize the interference with the surrounding colleagues. Comparison of office simulation results with and without CCRs shows that there can be a 4-fold difference in speech pressure level in the space. By combining acoustic modeling with architectural design, this research demonstrates how interdisciplinary approaches can create adaptive, sound-responsive interfaces that enhance office acoustics.